Numerical Analysis of Large Pipe Roof Support Reinforcement in Shallow Expansive Loess Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 1572-1576
Author(s):  
Bang Shu Xu ◽  
Zhong Yi Zeng ◽  
Cheng Chen ◽  
Lei Wang
Keyword(s):  
Numerical Analysis ◽  
Finite Difference ◽  
Plastic Flow ◽  
Soft Soil ◽  
Surrounding Rock ◽  
Reinforcement Effect ◽  
Soil Pressure ◽  
Tunnel Face ◽  
Under Construction ◽  
Roof Support

Xiaohegou tunnel is an under construction shallow expansive loess tunnel with Large Pipe Roof Support. Large Pipe Roof Support construction and excavation of the tunnel was simulated by the Fast Lagrangian finite difference software Flac3D. The pipe roof loading states and the deformation of surrounding rock in front of the tunnel face was obtained in each step of excavation, and the results was compared with a simulation without Large Pipe Roof Support. The results show that the reinforcement effect of Pipe Roof was to restrain the plastic flow of soft soil, and Pipe Roof help to share soil pressure, which could decrease the tunnel deformation effectively.

scholarly journals Stability Analysis of Shallow and Bias Loess Tunnel Based on Finite Difference Method

2019 ◽  
Vol 131 ◽  
pp. 01027
Author(s):  
Li Yongbing ◽  
Binglei Li ◽  
Guanyu Hua ◽  
Xinran Jia ◽  
Yanqiao Chen ◽  
...  
Keyword(s):  
Finite Difference ◽  
Shear Failure ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Failure Zone ◽  
Tunnel Face ◽  
Whole Process ◽  
The Earth ◽  
Practical Engineering ◽  
The Stability

Based on the Mohr-Coulomb elastic-plastic model and the practical engineering background of Mopanshan tunnel, this paper applies the finite-difference software FLAC3D to simulate and analyse the whole process of loess tunnel construction. Then, it analyses the stability of the surrounding rock and sup-port structure after partial excavation of the loess tunnel under the shallow burying and unsymmetrical load-ing condition. The study showed that in the absence of support, the shear failure occurred to the top/upper pilot tunnel of the tunnel face, the failure zone under tensile stress happened to the shallow soil of the earth surface, and the soil of tunnel face appeared to be damaged. Finally, according to the analysis results, a rea-sonable construction method suitable for the shallow and bias loess tunnel is determined.

The Numerical Analysis on Stability of Deep Roadway Support System

2012 ◽  
Vol 193-194 ◽  
pp. 687-692
Author(s):  
Zhen Yan Xiao ◽  
Yu Liu
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Support System ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Reinforcement Effect ◽  
Rock Bolts ◽  
Roadway Support

The effect of the roadway with no supporting and roadway that was reinforcement by rock bolts and anchor robs, anchor rod combined bolting shoring, anchor rod combined anchor rope and lining timbering was simulated by using numerical simulation software FLAC3D. The results showed that the deformation of no supporting roadway is maximal, and the maximal position is vault. The displacement of top floor and two side decreases after supported, which can reinforce surrounding rock. The reinforcement effect of the anchor rod combined anchor rope and lining timbering is best.

Optimization of Excavation Method in Portal Section of Neighborhood Tunnel Based on the Monitoring Results

2013 ◽  
Vol 645 ◽  
pp. 515-518
Author(s):  
Jun Min Shen ◽  
Zhong Ming Su ◽  
Xiao Hui Xue
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Analytical Model ◽  
Surrounding Rock ◽  
Blasting Vibration ◽  
Step Method ◽  
Dynamic Design ◽  
Tunneling Method ◽  
Roof Support ◽  
Design And Construction

Based on the excavation of portal section in Linwu neighborhood tunnel, items of the blasting vibration, vault settlement and level convergence are measured in the field construction. And according to the actual exposed surrounding rock, the finite element analytical model is established. The results of monitoring measurement and numerical analysis indicate that, under the circumstances of advance large pipe-shed roof support and varied surrounding rock, the original excavation method is not reasonable, still existing the optimization space. The construction of changed step method is feasible, which reflects the requirement of dynamic design and construction in New Austrian Tunneling Method.

Numerical Analysis of Soft Soil Ground Consolidation Settlement

2014 ◽  
Vol 638-640 ◽  
pp. 503-506 ◽  
Author(s):  
Jin Fang Hou ◽  
Ju Chen ◽  
Xiao Qiang Kou
Keyword(s):  
Numerical Analysis ◽  
Soft Soil ◽  
High Water ◽  
High Water Content ◽  
Surcharge Preloading ◽  
Open Sea ◽  
Consolidation Settlement ◽  
Calculation Results ◽  
Settlement Property ◽  
Under Construction

An artificial island under construction is located at an open sea and constructed by such a way that island walls are composed of steel cofferdams inserted into impermeable layers and then filled with sands. Grounds on the island are covered by thick soft soil layers with high water content, large compressibility and low bearing capacity, and treated by a jointed dewatering surcharge preloading method. In order to know the settlement property of the soft soil ground, the numerical analysis is implemented. During the analyzing, the parameters are adjusted and calculated through inverse analysis compared with practical measured data. So the numerical calculation results are more reliable. The analysis results indicate that the residual settlement of the soft soil ground is 9cm, and main ground consolidation settlement will be completed for two years after construction finished.

Research on Mechanical Behavior of Pipe-Roof Reinforcement Applied in Tunnel Based on MATLAB

2013 ◽  
Vol 353-356 ◽  
pp. 1394-1397
Author(s):  
Zhi Jie Sun ◽  
Jun Min Shen ◽  
Zhong Ming Su ◽  
Xiao Hui Xue
Keyword(s):  
Mechanical Behavior ◽  
Elastic Foundation ◽  
Beam Theory ◽  
Surrounding Rock ◽  
Tunnel Face ◽  
Pasternak Elastic Foundation ◽  
Mechanical Models ◽  
Support Conditions ◽  
Elastic Foundation Beam ◽  
Roof Support

Based on the Pasternak elastic foundation beam theory, mechanical models solving process of pipe-roof based on the MATLAB is elaborate, and the mechanical behavior of pipe-roof reinforcement is analyzed. Results show that the pipe-roof can play an leveraged part in surrounding rock, which can make the deformation and the load around tunnel face effectively passing to no excavation section near the excavation. In pipe-roof support conditions, the longitudinal influence scope of tunnel due to excavation is about 1.3~1.5 times the excavation height.

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